linux-kernel - Re: [PATCH v2 3/3] IB/core: Obtain subnet

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <9441568B-DBB7-4C4A-B6E7-5D19912C209E@oracle.com>
Date:   Thu, 3 Jun 2021 12:50:36 +0000
From:   Haakon Bugge <haakon.bugge@...cle.com>
To:     Mark Zhang <markzhang@...dia.com>
CC:     Anand Khoje <anand.a.khoje@...cle.com>,
        OFED mailing list <linux-rdma@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "dledford@...hat.com" <dledford@...hat.com>,
        "jgg@...pe.ca" <jgg@...pe.ca>, "leon@...nel.org" <leon@...nel.org>
Subject: Re: [PATCH v2 3/3] IB/core: Obtain subnet_prefix from cache in IB
 devices



> On 3 Jun 2021, at 14:10, Mark Zhang <markzhang@...dia.com> wrote:
> 
> On 6/3/2021 2:50 PM, Anand Khoje wrote:
>> External email: Use caution opening links or attachments
>> ib_query_port() calls device->ops.query_port() to get the port
>> attributes. The method of querying is device driver specific.
>> The same function calls device->ops.query_gid() to get the GID and
>> extract the subnet_prefix (gid_prefix).
>> The GID and subnet_prefix are stored in a cache. But they do not get
>> read from the cache if the device is an Infiniband device. The
>> following change takes advantage of the cached subnet_prefix.
>> Testing with RDBMS has shown a significant improvement in performance
>> with this change.
>> The function ib_cache_is_initialised() is introduced because
>> ib_query_port() gets called early in the stage when the cache is not
>> built while reading port immutable property.
>> In that case, the default GID still gets read from HCA for IB link-
>> layer devices.
>> Fixes: fad61ad ("IB/core: Add subnet prefix to port info")
>> Signed-off-by: Anand Khoje <anand.a.khoje@...cle.com>
>> Signed-off-by: Haakon Bugge <haakon.bugge@...cle.com>
>> ---
>>  drivers/infiniband/core/cache.c  | 7 ++++++-
>>  drivers/infiniband/core/device.c | 9 +++++++++
>>  include/rdma/ib_cache.h          | 6 ++++++
>>  include/rdma/ib_verbs.h          | 6 ++++++
>>  4 files changed, 27 insertions(+), 1 deletion(-)
>> diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
>> index b6700ad..724ac0e 100644
>> --- a/drivers/infiniband/core/cache.c
>> +++ b/drivers/infiniband/core/cache.c
>> @@ -1624,6 +1624,8 @@ int ib_cache_setup_one(struct ib_device *device)
>>                 err = ib_cache_update(device, p, true);
>>                 if (err)
>>                         return err;
>> +               set_bit(IB_PORT_CACHE_INITIALIZED,
>> +                       &device->port_data[p].flags);
>>         }
>>         return 0;
>> @@ -1639,8 +1641,11 @@ void ib_cache_release_one(struct ib_device *device)
>>          * all the device's resources when the cache could no
>>          * longer be accessed.
>>          */
>> -       rdma_for_each_port (device, p)
>> +       rdma_for_each_port (device, p) {
>> +               clear_bit(IB_PORT_CACHE_INITIALIZED,
>> +                        &device->port_data[p].flags);
>>                 kfree(device->port_data[p].cache.pkey);
>> +       }
>>         gid_table_release_one(device);
>>  }
> 
> Do we need to clear it in gid_table_cleanup_one()?

Good point. Is it feasible that ib_query_port() can be called on a device that has been removed? If yes, we need it in gid_table_cleanup_one() as well.


Thxs, Håkon